Do not copy matrices

Author: certik

src/linalg.f90

@@ -36,17 +36,15 @@ subroutine deigh_generalized(Am, Bm, lam, c)
     call assert_shape(c, [n, n], "eigh", "c")
     lwork = 1 + 6*n + 2*n**2
     liwork = 3 + 5*n
-    allocate(Bmt(n,n), work(lwork), iwork(liwork))
-    allocate(Amt(n,n))
+    allocate(work(lwork), iwork(liwork))
     allocate(ifail(n))
-    Amt = Am; Bmt = Bm  ! Bmt temporaries overwritten by dsygvd
     !call dsygvd(1,'V','L',n,c,n,Bmt,n,lam,work,lwork,iwork,liwork,info)
     il = 1
     iu = 7
     M = iu-il+1
     allocate(z(n,M))
     abstol = 1e-4_dp
-    call dsygvx(1,'V','I','L',n,Amt,n,Bmt,n, &
+    call dsygvx(1,'V','I','L',n,Am,n,Bm,n, &
         0._dp, 0._dp, 1, 7, abstol, M, lam, c, n, work, &
         lwork, iwork, ifail, info)
     !SUBROUTINE DSYGVD( ITYPE, JOBZ, UPLO, N, A, LDA, B, LDB, W, WORK, &